DE69530740T2 - Image processing device - Google Patents

Description

BACKGROUND THE INVENTION

(1) Field of the Invention

The present invention relates an image processing device such as digital Copiers, fax machines, Printers and the like and in particular on an image processing device, in the image information using image processing to desired Features can be processed.

(2) Description of the stand of the technique

The past few years have been electrophotographic Copiers have come into wide use and are digital copiers has been put into practical use. With the spread of the Digital copiers are different types of image processing techniques has been developed using an original manuscript these techniques easily processed and as by means of image processing processed duplication can be played. For example, the one disclosed Japanese Patent Application Hei 4 No. 218,879 an image processing device of the prior art, the filling treatment, an outline treatment, performs shading treatment and the like.

In the above devices the input image data is converted into binary data by means of image input means and the data thus binarized is stored in line memories. When the outline generation conversion is to take place, the data subjected to N × N matrix logic operation in these line memories to receive binary data generate that represent the outlines. If the shading operation the binary data in the line memories in the 45 ° direction transferred to the top right, to generate shading data. The size of the storage area to use is in agreement in this processing with the content of the to be executed Image processing changed.

In this way, the over Image input means inputted into the above device Data in binary data implemented, which in turn are processed by means of bid processing. Accordingly, no more than two could be represented by '0' and '1' colors are represented, which is only a low level of expression and bad picture quality revealed. This means, the above conventional Configuration could not meet the demands of high quality workmanship fulfill, if at the time of the bid processing the reproduction of a high quality Desired picture was. While the demand for high quality images continues to spread it is necessary to treat multivalued data. However the multivalued data a few times more massive than that binary data so the processing time tends to get long. Accordingly will also image processing with improved processing efficiency desired. The above Technology should only focus on improving utility efficiency the memory by minimizing the required number of memories, which were intended when the image processing treatment was carried out his. This means, in the revelation no suggestion was made that either Image processing simplified or the quality of the images improved, so that the technology cannot meet the above requirements.

• (1) Falls alle Bildelemente 1), 2) und 3) weiß sind (die Dichte null ist), erfolgt keine Halbtonumsetzung;
• (2) falls das Bildelement 4) oder 5) weiß ist (die Dichte null ist), erfolgt keine Halbtonumsetzung;
• (3) eine Halbtonbildung wird ausgeführt, wenn entweder die obige Bedingung (1) oder die obige Bedingung (2) erfüllt ist; und
• (4) die obige Prozedur (1) bis (3) wird wiederholt, um über das gesamte Eingangsbild Punktmuster zu entwickeln und dadurch eine Halbtonbildung auszuführen.

Examples of the image processing not mentioned in the above technique include a halftone process which is carried out in the following manner. That is, in order to halftone an image, the input image data as in FIG 1 is analyzed, pixel by pixel, in accordance with the following rules:

• (1) If all picture elements 1), 2) and 3) are white (the density is zero), there is no halftone conversion;
• (2) if the picture element 4) or 5) is white (the density is zero), there is no halftone conversion;
• (3) halftoning is carried out when either the above condition (1) or the above condition (2) is satisfied; and
• (4) The above procedure (1) to (3) is repeated to develop dot patterns over the entire input image and thereby perform halftoning.

However, the original could Image will deteriorate if the entire image is halftoned executed with dots becomes. To avoid this deterioration, the pixel data must be checked to look for outline parts in the image so that on the edge parts and therefore there is no halftone formation. However, this takes time Procedure long time. Consequently, this procedure can meet the requirement due to the simplification of image processing.

However, the document reveals EP-A-0 406 084 an image forming device with shadow generation for reproducing an image from a binary serial signal to which a shadow signal has been added in a certain area is a white one Section between black sections of a binary original image is recorded as a shadow area.

Document FR-A-2 also relates 588 398 to an image processing system that uses shading and edge processing enables being in the shading for an original Picture as well Silhouettes are delivered while it is moved several times becomes.

In addition, document US-A-4 729 038 teaches a laser recording device as described in Using a laser beam with three different intensities can perform a shadow printing operation for character data, the third intensity being an intensity between a first and a second intensity, which depending on a specific relationship of the binary input data at a position along a horizontal line at which the significance of the binary input data changes, is created.

SUMMARY THE INVENTION

Given the subject discussed above thus an object of the present invention to provide Image processing device, its image processing speed is improved and that can provide a good picture that is free of deterioration in image quality.

This object is achieved according to the invention solved by an image processing device as defined in claim 1 is.

Advantageous further developments are the subject of the attached dependent claims.

Briefly described, the image processing device builds of the present invention for any picture element (which can be an observed picture element should) in the original Image a matrix so that the density of the observed pixel and that of a target pixel or of target pixels that are in the Related to the mode of image processing selected to determine a maximum value of the density of these picture elements. If the density of the observed picture element is greater than is that of the target picture element or elements, the Density of the target picture element or the target picture elements in a predetermined Density level implemented while then when the density of the observed picture element is less than that of the target image element or elements is not implemented the density occurs. This procedure is used for all image information repeatedly executed to thereby creating a processed image. Then the processed Image with the original Image combined, creating a desired Image that is directed to the particular mode of operation is completed.

If an original document has malfunctions such as Stains, dust, etc., the image quality of the duplication of the original deteriorates because these disturbances are also processed using image processing are processed. To avoid this, the device compares the density of an observed picture element with a given one Value to determine whether the picture element in question is a disorder is or not. If it is determined that the observed picture element a disturbance is the image processing for the image element is locked in order to avoid unnecessary image processing, so the quality of the image can be improved in image processing.

SUMMARY THE DRAWING

1 Fig. 12 is a view for explaining a conventional halftone process;

2 Fig. 12 is a view showing an overall configuration of a digital copier in accordance with an embodiment of the present invention;

3 Fig. 12 is a block diagram showing configurations of an image processing system and other control systems in the digital copier in accordance with the embodiment of the present invention;

4 Fig. 12 is a view showing a control panel in the digital copier in accordance with the embodiment of the present invention;

5 Fig. 12 is a view showing a control block diagram for processing images in the digital copier of the embodiment of the present invention;

6 Fig. 12 is a view showing a display state on the halftone mode setting panel;

7 Fig. 11 is a view showing a display state on the field for setting a shading and relief mode;

8th Fig. 3 is a view showing a 3 x 3 matrix;

9 Fig. 12 is a view showing an original picture;

10A Fig. 3 is a view showing a 3 x 3 matrix filter;

10B Fig. 12 is a view showing a state in which the original image is covered with the filter;

11 Fig. 12 is a view showing a shading image;

12 is a view showing the original image with shadows;

13A Fig. 12 is a view showing the data of an original image to be subjected to a shading operation;

13B Fig. 14 is a view for explaining the procedure for creating a silhouette for the shading operation;

13C Fig. 12 is a view showing a shaded image created by combining the original image with the shaded image;

14 Fig. 14 is a table for converting density in a case where the density of a target picture element is not converted;

15 Fig. 14 is a table for converting density in a case where the density of a target picture element is converted;

16A Fig. 12 is a view showing a shaded image in which a stain is shaded;

16B Fig. 12 is a view showing a shaded image produced by an image process in such a way that no shadow is added to a stain;

17 Fig. 12 is a view showing examples generated by shading modes in the invention and in the conventional art;

18A Fig. 12 is a view showing a shaded image in which a stain is shaded;

18B Fig. 12 is a view showing a shaded image created by an image process such that no shadow is added to a stain;

19 Fig. 3 is a table showing a matrix to be constructed for isolated stains;

20 Fig. 14 is a density table showing an example of setting the shading density;

21A Fig. 3 is a 3 × 3 matrix filter for creating shadows that run below 45 ° to the bottom left;

21B is a shaded image when creating shades that are 45 degrees lower left;

22 is a shadow density conversion table for generating dark shadows;

23 is a shadow density conversion table for generating light shadows;

24A is a 3 × 3 matrix filter for creating shadows that are 45 ° to the top left;

24B is a shaded image when creating shades that are 45 degrees to the top left;

25 Fig. 12 is a view showing an image in which a 2x4 repeat copy is made;

26 Fig. 12 is a view showing a shaded image in which a false shadow is generated in a rotated image;

27 Fig. 12 is a view showing a shaded image in which a correct shadow is created in a rotated image;

28 Fig. 12 is a view showing an expanded image in the shading and relief mode;

29 Fig. 12 is a view showing an expanded image with a shadow added;

30 Fig. 12 is a view showing a shaded and relief image;

31A Fig. 12 is a view showing an original image with a spot;

31B Fig. 12 is a view showing a shaded and embossed image in which a stain has been shaded and embossed;

32 Fig. 12 is a view showing examples generated by the shading and relief mode in the invention and in the conventional art;

33A Fig. 12 is a view showing a processed image in which no shading density conversion is produced for the spots;

33B Fig. 12 is a view showing a shaded and embossed image which has been processed by image processing without a spot having been shaded and embossed;

34A Fig. 4 is a view showing a shaded and relief image in which a stain has been shaded and relief:

34B Fig. 12 is a view showing a processed image in which shading density conversion is not carried out for spots;

34C Fig. 12 is a view showing a shaded and embossed image which has been processed by image processing without a spot having been shaded and embossed;

35A Fig. 4 is a view showing a shaded and relief image in which a stain has been shaded and relief:

35B Fig. 12 is a view showing a processed image in which no shading density conversion is carried out for the spots;

35C Fig. 12 is a view showing a shaded and embossed image which has been processed by image processing without a spot having been shaded and embossed;

36A Fig. 4 is a view showing an image in relief with a spot in relief:

36B Fig. 12 is a view showing a processed image in which no relief operation is performed for spots;

36C Fig. 12 is a view showing a relief image processed by image processing without relief of a spot;

37 Fig. 12 is a view showing examples generated by the relief forming modes in the suffix and in the conventional art;

38 Fig. 12 is a view showing a processed image expanded in the halftone mode;

39A Fig. 12 is a view showing a raster pattern;

39B Fig. 12 is a view showing a raster image;

40 Fig. 12 is a view showing a halftone image;

41A Fig. 12 is a view showing an original image with spots;

41B Fig. 12 is a view showing a processed image in which the spots are expanded;

41C Fig. 12 is a view showing a raster image in which the spots are halftone;

42A Fig. 12 is a view showing a processed image in which no stain is expanded; and

42B Fig. 14 is a view showing a halftone image processed by image processing with no spot covered with a raster.

DESCRIPTION OF THE PREFERRED EMBODIMENTS

2 shows a digital copier A with built-in facsimile machine having an image processing device of the present invention. As shown in the figure, the digital copier contains A an image scanning system 1 , a laser printer system 2 , a multi-sheet paper chute 3 and an automatic sorter 4 ,

The image scanning system 1 contains an original table 5 made of clear glass, an automatic reverse document feeder (RDF) 6 and an image scanner unit 7 , In the RDF 6 several previously arranged original documents are sent individually to the image scanner unit 7 shipped so that the image scanner 7 in accordance with the selection made by the operator, can include the content of the document on one or both sides. The image scanner unit 7 contains a lamp reflector assembly 8th to illuminate the document, multiple reflection mirrors 10 for introducing the reflected light from the document to a photoelectric transmission device (CCD) 9 and a lens 11 to focus the reflected light from the original document onto the surface of the CCD 9 , producing a reflected light image.

The image scanning system 1 is configured so that the image scanner unit 7 along the bottom of the original table 5 moved to take the original image on the document when the original document is on the original table 5 is arranged to scan it; while the original document is being moved, while the image scanner unit 7 at a given location under the RDF 6 is positioned when the RDF 6 used to capture the original image on the document.

That in this way by means of the image scanner unit 7 Image data taken from the original image is sent to an image processing system where the image data undergo various processes. The image data processed in this way is temporarily stored in a memory. The image data is then sent to the laser printer system in response to an output instruction 2 transmitted, which creates the image on a sheet of paper.

The laser printer system 2 contains a paper chute 14 for manual sheet feeding, a laser printing unit 15 and an electrophotographic processing unit 16 to generate the images. The laser printing unit 15 contains a semiconductor laser 17 , which emits laser beams in connection with the image data from the above-mentioned memory, a polygon mirror which deflects the laser beams at an angle-correct rate, an f-θ lens for correcting the laser beams deflected at an angle, so that the laser spot linear at a uniform speed on a light receiving drum 18 the electrophotographic processing unit 16 can move.

Around the light receiving drum 18 in the electrophotographic processing unit 16 are a charging device 19 , a development unit 20 , a transmission unit 21 , a separator 22 , a cleaning unit 23 , a cargo unloader 24 and a fuser 25 arranged. On the exit side of the fuser 25 or on the side to which the sheet with the image generated on it from the fusing unit 25 is ejected is a sheet transport path 30 arranged. This sheet transport route 30 is branched in two ways: in a sheet transport route 31 with the sorter 4 is connected, and in another sheet transport path 32 with the multi-sheet paper chute unit 3 connected is.

The sheet transport path is further 32 in the multi-sheet paper chute unit 3 in two sheet transport paths, ie in one sheet reversal path 33 and in a double-sided joining transport path 34 , branches. The leaf reversal path 33 serves as the sheet transport path for reversing the back of the sheet upward in the double-sided copying mode in which copying is carried out on both sides of the sheet. The double-sided assembly transport route 34 is used to move the sheet in the double-sided copy mode from the sheet reversal path 33 to the imaging station on the light receiving drum 18 to transport. This transport route also serves 34 to the sheet in the single-page merge copy mode, in which various original images are to be assembled on one page or in which different color toners are used to form an image on one page, to the imaging station at the light receiving drum 18 to transport without reversing it.

The multi-sheet paper chute unit 3 has a first, a second and a third cassette 35 . 36 and 37 and also contains a fourth cassette 38 that can optionally be added. The multi-sheet paper chute unit 3 has a common sheet transport path 39 which is arranged so that the sheets held in each cassette are individually fed from above to the electrophotographic processing unit 16 can be delivered. This common sheet transport route 39 and another sheet transport route 40 from the fourth cassette 38 come in a sheet transport route 41 on the way to the electrophotographic processing unit 16 together. This sheet transport route 41 is arranged to be with the double-sided joining transport path 34 and with that Sheet transport 42 from the paper chute 14 for the manual sheet feed comes together and between the light receiving drum 18 and the transmission unit 21 in the electrophotographic processing unit 16 is connected to the imaging station. That is, the meeting point of these three transportation routes is located near the imaging station.

In this arrangement, the laser beams are in the laser writing unit 15 as modulated on the basis of the image data loaded from the memory onto the surface of the light receiving drum 18 in the electrophotographic processing unit 16 scanned to form an electrostatic latent image on the surface. The latent image is developed with toner. The visualized toner image is electrostatically transferred to the surface of the sheet by the multi-sheet paper chute unit 3 is delivered, and fixed on it in the fuser. The sheet with the image generated in this way is by means of the sheet transport paths 30 and 31 from the fuser 25 to the sorter 4 transported or via the sheet transport routes 30 and 32 to the leaf reversal path 33 sent out.

Below are based on 3 the configurations and functions of the image processing system and other control systems contained in the digital copier are described. 3 Fig. 10 is a block diagram showing an image processing system and another control system used in the digital copier A with built-in fax machine are included. A reference number 50 in the figure, denotes an image data input unit that has a CCD section 50a , a histogram processor 50b and an error spreading processor 50c contains. A reference number 51 denotes an image processing unit that the value creation processors 51a and 51b , an image change / edit / composition processor 51c , a density conversion processor 51d , an enlargement / reduction processor 51e , an image processor 51f , an error spreading processor 51g and a compression processor 51h contains. A reference number 52 denotes an image data output unit that a recovery section 52a , a value creation processor 52b , an error spreading processor 52c and a laser output section 52d contains. The reference numbers 53 . 54 and 55 each designate a memory, a control panel and an image processing CPU (image processing central processing unit). 4 is an enlarged view of the control panel 54 with an LC sensor field control screen that has a paper tray select button 56 , Magnification adjustment buttons 57 , Copy density adjustment buttons 58 , a function selection button 59 and a display section 60 contains. When the function selection button 59 is pressed, the screen page is switched.

That in the digital copier A included image processing system contains the image data input unit 50 , the image processing unit 51 , the image data output unit 52 , the store 53 from RAMs (read-write memories) etc. and the image processing CPU 55 ,

The image data input unit 50 contains the CCD section 50a , the histogram processor 50b and the error spreading processor 50c , The image data input unit 50 is designed to work as follows. That is, by means of the CCD 9 Image data recorded from the original document are binarized and processed by generating a histogram based on the binary digital quantities. Then, the image data processed in this way is temporarily stored in the memory 53 saved. That is, in the CCD section 50a analog electrical signals representing the image density of the image data are A / D converted, whereupon the digital signal is subjected to MTF correction (modulation transfer function correction), black and white correction or gamma correction, with the output signal for each picture element as a digital signal which Represents 256 hues (8 bits), the histogram processor 50b is fed.

In the histogram processor 50b by adding the number of bit elements that have the same density level according to the classification of 256 hues, the density information (represented by histogram data) is obtained. The histogram data obtained in this way is processed by the image processing CPU 55 supplied and as pixel data to the error spreading processor 50c Posted. In the error spreading processor 50c be those of the CCD section 50a Output digital signals, each having 8 bits per picture element, converted into 2-bit signals (quaternary signals) by the error spreading method as a kind of pseudo intermediate processes or by the method in which quaternary errors are used to determine the quaternaryization of the neighboring picture elements. The redistribution operations are performed to faithfully reflect the densities of local areas in the original document.

The image processing unit 51 contains the value creation processors 51a and 51b , the image change / edit / composition processor 51c , the density conversion processor 51d , the enlargement / reduction processor 51e , the image processor 51f , the error spreading processor 51g and the compression processor 51h , The image processing unit 51 Outputs the finished image data desired by the operator by entering the input image data according to that provided by the control panel 54 instructed image processing mode implements. That is, this processing unit is designed to process the input image data until the finally converted output image data is completely in the memory 53 saved are. Any of the above in the image processing unit 51 contained processors work here as needed and should not work necessary.

The value-added processors are changing more precisely 51a and 51b that in the error spreading processor 50c quaternary data back into 256-valued data. The image change / edit / composition processor 51c performs a logical operation, ie a logical OR, a logical AND or an exclusive OR, for each picture element. This logic operation is for those in memory 53 stored image data and for the bit data executed by a pattern generator (PG).

The density conversion processor 51d based on a predetermined gradation conversion table in accordance with an instruction on the copy density keys 58 on the control panel 54 with respect to the digital signals representing 256 density tones, any relationship of the output densities to the input densities.

The enlargement / reduction processor 51e performs on the basis of the known input data in accordance with one by the magnification adjustment key 57 on the control panel 54 determined magnification an interpolation to thereby determine pixel data (a density value) which represents a changed-size pixel with respect to the changed-size target pixels. The image data is updated by sequentially converting the image data in the auxiliary scanning direction and then in the main scanning direction based on the newly determined picture element data.

In the image processor 51f the input pixel data are exposed to various types of image processing. The image processor can also 51f make a compilation of information such as a feature extraction and the like on the data sequences. In the error spreading processor 51g a similar process to that in the error spreading processor is performed 50c the image data input unit 50 is performed. The compression processor 51h compresses the binary data based on a coding scheme called run length coding. On the other hand, in the last processing loop, when the final output image data is completely generated, compression of the image data is carried out.

The image data output unit 52 contains the recovery section 52a , the value creation processor 52b , the error spreading processor 52c and the laser output section 52d , The image data output unit 52 is configured as follows. The unit 52 puts those in memory 53 stored compressed image data back to the initial state and converts the restored data back into the data of the original image with 256 sealing tones. The image data output unit then leads 52 based on quaternary data that can be used to represent halftone gradations more smoothly than with binary data. The data processed in this way is sent to the laser output section 52d transfer. The compression processor makes them more precise 51b compressed image data in the recovery section 52a restored to its original condition. In the value creation processor 52b a similar process is carried out as in the value creation processors 51a and 51b the image processing unit 51 is performed. In the error spreading processor 52c a similar process to that in the error spreading processor is performed 50c in the image data input unit 50 is performed. In the laser output section 52d the digital image data are converted into switching signals for the semiconductor laser on the basis of control signals from a sequence control device (not shown) 17 implemented so that the semiconductor laser 17 is switched on and off.

Accordingly, the pixel data representing 256 hues for each pixel becomes in the image processing unit 51 quantized into compressed pixel data representing 4 hues for each pixel. The image data quantized in this way is used to determine the output width (illumination time) of the laser beams from the semiconductor laser for each picture element (point) 17 to determine. In other words, the pixel data with four tones for each pixel is changed by changing the output width of the laser beams from the semiconductor laser 17 brought into a gradation representation.

A copier A This embodiment has image processing functions for changing and editing images such as shading, relief, and halftoning. That is, as in 5 is shown contains the copier A : Operating mode setting means 70 to select an image processing mode for shading, embossing and halftoning, and combinations thereof; Image formation control means 71 for controlling image generation based on the input image information; Image processing means 72 for controlling the image information based on a selected image processing mode; and image information input means 73 such as the CCD 9 for inputting image data to the image generation control means 71 , The mode setting means contain more precisely 70 Function selection buttons and the like on the control panel 54 , The imaging control means 71 are through the image processing CPU 55 , the store 53 and the like embodied. The image processing equipment 72 contain the image processing means 51 , the image data input unit 50 and the image data output unit 52 ,

The image processing equipment 72 perform the following basic functions for image processing out. That is, the image processing equipment 72 perform: a determination function in which the image information input means 73 captured image data are converted into binary or multi-value data and in which one or more target image elements to be compared with an observed image element are determined in accordance with a selected image processing mode; a comparison function for comparing the density of the target pixel or the target pixels with that of the observed pixel; a conversion function for converting the density of the target pixel or the target pixels based on the result of the comparison; and a function to discriminate, based on the density information of the observed picture element, whether the image data in a observed picture element is interference and to inhibit the image processing when it is determined that the data is an interference. Here, the observed picture element means a picture element which is observed on an original and is to be processed by means of image processing, while the peripheral picture elements indicate those which enclose the observed picture element, and furthermore the target picture elements indicate those which are subject to image processing such as shading and the like are to be suspended.

They also have the means 72 Functions that are characteristic of every image processing mode. More specifically, the characteristic functions for the shading mode include: a function for stopping the conversion of the density of target picture elements or for blocking the image processing when the density of an observed picture element is equal to or less than the shading density or when an observed picture element has a predetermined quantized density value; a function for distinguishing the density of a target picture element or target picture elements from that of an observed picture element when the density of the target picture element or the target picture elements is implemented in relation to the observed picture element, or in particular a function for reducing the density of the target picture element or the target picture elements, if the shading image is to be distinguished from the original image; a function for changing the density of the shading; and a function for setting any direction of shading in the image information on the target picture element or elements. To deal with a case where shading is performed on a rotated image, the means have 72 a function of determining a direction of shading for the image information on the rotated image. The image processing means also have 72 for dealing with a case where the arrangement direction of an original document does not match that of the transfer paper, a function of determining the direction of the original and the direction of the transfer paper to compare the directions with each other and to rotate the image information if the directions differ; a function to determine, based on the rotated direction of the image, a direction of a target pixel or pixels to be shaded with respect to an observed pixel; and a function to compare the density of the observed target picture element or the observed target picture elements with respect to the observed picture element and to implement the density of the target picture element or the target picture elements.

The image processing means lead for the relief formation mode 72 A function for expanding peripheral picture elements of an observed picture element by a prescribed amount; and a function of removing the original image information from the expanded image information by performing logic operations. The image processing means lead for the shading and relief mode 72 The following: a function for expanding peripheral picture elements by an observed picture element in a predetermined quantity; a function for generating shadows in a predetermined direction based on the image information after the expansion; and a function of removing the information of the original picture from the expanded picture information by performing logic operations. If the density of the target picture element or the target picture elements is to be implemented in the shading and in the relief formation mode in relation to the observed picture element, the means contain 72 a function for differentiating the density of the target picture element or the target picture elements, in particular for increasing the density of the target picture elements for improving the sharpness of the outline; and a function for stopping the conversion of the density of the target picture elements or for blocking the image processing when an observed picture element has a predetermined quantized density value.

The means for the halftone mode 72 a function for expanding the peripheral picture elements by an observed picture element in a predetermined amount; a function for preparing special image pattern information; a function for removing the image information after the expansion from the prepared image pattern information; a function of adapting the information of the original image to the image pattern information from which the image information of the expanded image is removed by performing logic operations; and a function for sequentially performing expansion operations for each picture element without executing the expansion of the image information when the density of an observed picture element is less than a predetermined quantized value.

Practical procedures for performing each of the image processings will now be described. If at the beginning the function selection button on the control panel 54 is pressed to select one of the image processing modes, as in 6 a halftone mode setting page is displayed. As in 7 is shown, pressing the function selection key also causes the display to display another setting page for the shading and relief mode. This setting page displays three modes, that is, the shading mode, the shading and relief mode, and the relief mode, so that a user can select one of them.

When the user selects the shading mode, he should have an original on the original table 5 or on the original feeder (RDF) 6 arrange and press the copy start button. As the operation begins, the scanner unit picks up 7 the original image from the arranged document. The image data recorded in this way are transferred via the image data input unit 50 In the storage room 53 stored so that in the image processing unit 51 different processing can be performed. First, the image data in the error spreading processor 50c in the image data input unit 50 quantized to quaternary data. The data quantized in this way is stored in memory 53 stored and by the value creation processor 51a managed without being converted into 256-valued data by the added value process. When the shading mode is selected, the image change / edit / composition processor 51c through one like in 8th 3 × 3 matrix shown performed image processing of the image data. This matrix is well known and is the one normally used in the field. In this image processing a code is built up in order to form a maximum value of the density between an observed picture element E and a target picture element I. That is, the processor 51c is operated so that it compares the density between the picture elements E and I. If the density of the picture element E (D _E ) is not less than that of the picture element I (D _I ) or D _E ≥ D _I , D _{I is} replaced by DE; while D _{I is} not changed if the density of the picture element E (D _E ) is less than that of the picture element I (D _I ) or D _E <D _I.

The like in 9 The data of the original image shown are supplied to the 3 × 3 matrix filter in the order (0.0), (1.0) ... (12.12), (13.12). A line buffer is arranged in front of the filter. In this arrangement, the filter acquires the ability to begin processing the data only after the first three lines have been entered into the line buffer. As in

10A is shown, the filter is preset such that it forms a maximum value of D _E and D _I while the other picture elements are masked. The data are fed from top left to bottom right. In one in 10B In the case shown, the observed picture element E has a density of level '3', while the shading target picture element I has a density of level '0' and while the other picture elements are masked. Thus, it is determined that its maximum value is '3', so that the shading target picture element I is output with a density of the level '3'. While the shading target picture element I is output with a density of level '3', the density conversion processor sets 51d the density of the shadow around so that the shading density is implemented such that it is, for example, '1'. This procedure is repeated to cover the entire page of the image, as shown in 11 is shown, a shadow image can be generated, which is offset from the original image at 45 ° by one point to the bottom right. In the final phase, the image change / edit / composition processor combines 51c the silhouette data generated in this way with that in the memory 53 stored data of the original image to complete the shading process. The image data generated in this way are from the image data output unit 52 the laser printer system 2 fed, which in turn, as in 12 an output image is completed with a one-point shadow.

In the shading operation above is the length of the shadow or how many points of the shadow are to be created determined by the number of repetitions of the image loop. If for example, the printer has a resolution of 400 dpi and shadows with a length of 0.5 mm are desired the image loop should be repeated eight times to get the image data with the desired one To complete shadows. If shadows of 1 mm are to be created, the image loop should can be repeated sixteen times, although a longer processing time is required for the increase is. Although the above description of the embodiment with reference to the quaternary data done, processing can be done here for data that has 256 values represent. If here quaternary data on 256-valued data are applied, '0', '1', '2' and '3' are each in '0', '85', '170' and '255' implemented.

• (1) Erzeuge aus einem ursprünglichen Bild durch Löschen aller beobachteten Bildelemente E mit einer Dichte vom Pegel '1' in den Daten des ursprünglichen Bildes ein Schattierungsbild (13A).
• (2) Vergleiche die Dichte jedes beobachteten Bildelements E mit der eines entsprechenden Zielbildelements I, um die maximale Dichte der Bildelemente zu bestimmen.
• (3) Setze die Schattendichte auf der Grundlage der Maximaldichte um.
• (4) Wiederhole die obigen Prozeduren (1) und (2) in Übereinstimmung mit einer angegebenen Schattenlänge mehrmals, um die Erzeugung eines Schattenbildes abzuschließen (13B).
• (5) Synthetisiere das Schattenbild mit dem ursprünglichen Bild, um das Schattenbild zu vervollständigen (13C).

The above shading process can be summarized by the following algorithm:

• (1) Create a shading image from an original image by deleting all observed image elements E with a density of level '1' in the data of the original image ( 13A ).
• (2) Compare the density of each observed pixel E with that of a corresponding target pixel I to determine the maximum density of the pixels.
• (3) Convert the shadow density based on the maximum density.
• (4) Repeat the above procedures (1) and (2) several times in accordance with a specified shadow length to complete the creation of a shadow image ( 13B ).
• (5) Synthesize the silhouette with the original image to complete the silhouette ( 13C ).

In order not to emphasize noise and not to deteriorate picture elements with middle gradations with relatively small density, as will be described later, it is assumed that any picture element with a density which is not greater than the level '1' (D _E ≤ 1) is one Disturbance is while any picture element with a density of level '2' or greater (D _E ≥ 2) is shaded. More specifically, the shading pixel is shaded at level '1' when the hue or density of an observed pixel is '3' or '2'; while the density of the shaded picture element is unshaded or shaded to the level '0' when the hue of an observed picture element is '1' or '0'.

In the above image processing, when an attempt is made to copy an original that contains a halftone, that is, gradations or color characters that are different from the black ones, while an in 14 shown shading process is performed, the following problem still occurs. That is, since the in 14 shown shading process produces shadows with a shading density of level '2', the density of the corresponding target picture element I is converted into the level '2' regardless of whether an observed picture element E has a density of level '1' or '2'. Accordingly, the halftone or midtone image is also shaded, thereby only damaging it, or the colored characters other than those colored in black are also shaded, so that the characters become blurred or thick. To avoid this, the system is arranged to compare the density of each observed pixel E with that of a corresponding shadow target pixel I when it is determined that the shadow element I has a density of level '2'. If the density of the observed picture element E is equal to or less than the shadow density, the system is adapted in such a way that it does not implement a shadow density conversion. Although it is assumed in this example that the shadow density is '2', the shadow density could be changed. In this way, since the observed picture elements are not shaded with light tones, neither blurring nor thickness occurs in the picture, nor is any halftone picture damaged. Accordingly, reproductions can be made which are free from deterioration of the images.

Meanwhile, if copying with an original document with stains and / or using the stained original table could 5 an invisible small dust (or noise) is recorded as image data, whereby even the noise is shaded. As in 16A shown becomes a stain more precisely D added a one-pixel shadow. If shadows with a length of 0.5 mm are created, there will be a spot D a shadow with eight picture elements attached. Thus, there is a tendency that insignificant disturbances are highlighted. In order to avoid this tendency, taking into account that disturbances caused by small contamination and dust have a low density, the processing scheme is constructed as follows. This means that a density quantized by means of a threshold value is built up for observed image elements E, so that image elements with low density can be neglected in the shading. The threshold density is set to level '1' here. If an observed picture element E has a density of level '1', the system stops the comparison between the observed picture element E and the target picture element I to determine the maximum of the two and the shading density conversion. When the copy operation is performed based on the scheme, the stain D , as in 16B is shown, not shaded. Although the above threshold density is set to level '1', this can be changed. 17 shows an example copy that was generated based on the above scheme. As can be seen from the example, no disturbances caused by pollution and stains, etc. are shaded and highlighted, so that a natural reproduction can be made which is free from deterioration of the images. This scheme is particularly effective when duplicating an original document that contains high-density characters and relatively larger characters.

Instead of the above embodiment, in which the shading can be blocked from interference by using the fact that the density of dust and the like is low, the shading can be blocked from interference by using dust and the like to isolate are. That is, if an in 18A is shown, disturbances due to dust, etc. are distinguished as follows. In order to avoid a misjudgment between faults and characters, a 3 × 3 matrix filter is initially used as in 19 shown constructed in such a way that the observed picture element E has a density with the level '1', while the other, enclosing picture elements have a density with the level '0'. When an observed picture element E has a density of level '1', the system compares the density between the observed picture element E and the shading target picture element I to determine the maximum men. In this case, if all the surrounding pixels have a density of the predetermined level (ie '0') and the density of the observed pixel E is less than the threshold density (ie '1' in this embodiment), the system determines that the one in question is observed Pixel E is a perturbation, and it does not perform the shading density conversion for the pixel. As in 18B as a result, the shading operation is performed as a result except for isolated spots of a single picture element. In this way, disturbances due to dust etc. can be distinguished from valid picture elements. As a result, a natural reproduction that is free from the deterioration of images can be produced without highlighting disturbances. This method is particularly effective when duplicating an original document that contains small characters.

On the other hand, if the density of the shadows is set close to that of the original image, it becomes difficult to distinguish the shadow from the original image. Alternatively, the character and shadow appear reversed if the density of the shadows is set darker than that of the original image, which makes the characters look thicker and more blurry, and thus degrades the image quality of the shaded image. Thus, the density of the shading pixel I should be set smaller than that of the observed pixel E when converting the density of the target pixels. 20 shows examples of the relationship between the density of the observed picture element E and that of the target picture element I in which a density relationship D _E > D _I holds. This setting condition makes the difference between the original image and the shading image clear in order to make a good starting copy.

In order to adjust the density of the shadow, a shadow can also be generated in positions other than the one described above or at 45 ° to the bottom right in this copier. For example, a condition for generating a shadow that runs at 45 ° to the lower left can be set via the setting page for the shading and relief mode. Under this condition, an in 21A picture element denoted by G to a new target picture element with respect to the observed picture element E. As in the case based on 11 described way, a maximum of these picture elements should be determined in the filter. Since the observed picture element E has a density of level '3' and the shading target picture element G has a density of level '0' while the other picture elements are masked, its maximum value is determined to be '3', so that the shading target picture element G is output with a density of level '3'. As a result, a shading image is created as shown in FIG 21B is shown by a hatched section. Since the shading target pixel G is output with the density of level '3', the density conversion processor sets 51d the density of the shadow in accordance with a (in 22 shown) conversion table in which converted values are related to the density levels. 22 shows an example in which the density of the shadow is set to the level '2'. If a lighter shadow is to be added, the density of the shadow will match that in 23 shown conversion table, in which the density of the shadow is set to '1', implemented. The above process is repeated until the shadow is given a certain length. The shading image thus generated is assembled with the original image, thereby completing the shading process. If shadows are to be created that are below 45 ° to the top left, an in 24A matrix filter as shown in 24B is shown, a shadow is created which runs at 45 ° to the top left. In this way, a user can create various types of shadows that run in a desired direction by selecting another target pixel from the matrix filter and allowing the selected pixel to perform logic operations on the observed pixel E. The user can also select a desired density of shadows. The combination of these features enables the copier to create a wide variety for the images.

As another mode of operation for processing and editing images, the copier has, as in 25 a repeat copy function is shown. This operating mode can be selected using the function selection button on the control panel 54 and allows, for example, an A4-size original document to be reproduced repeatedly in (2 × 4) or eight sections on A4-size paper. A case will now be considered in which an original is reproduced in the copy repeat mode while creating shadows which are 45 degrees to the lower right with respect to the original document. If the image processing CPU 55 which controls the entire copier, in this case instructing to rotate the image, the operation is carried out in the following manner. That is, if the operator has an original A4 size document on the original table 5 or on the original document feeder (RDF) 6 arranges, the original size sensor detects the size of the original document and recognizes it as A4. Since it is determined in this mode that the A4 size original is to be reproduced in 2 × 4 or eight sections on a sheet of the same size, that is, on A4 paper, the copy images cannot of course be fitted on the sheet if no data processing takes place. In order to fit the repeated copy images into the page, the image processing CPU instructs 55 the image processing equipment 72 to resize the image and rotate the image. An image on the arranged original is made by the image data input unit 50 processed and as image data in memory 53 stored, so that various processes in the image processing unit 51 can be executed. Initially, the error spreading processor makes the image data more precise 50c in the image data input unit 50 quantized into quaternary data and the quantized data temporarily in memory 53 saved. The image processing CPU then rotates 55 the image data by 90 ° clockwise. The image data rotated in this way is stored in the memory again 53 saved. The added value processor 51a converts the image data into 256-valued data. Then, the data processed in this way is enlarged in the enlargement / reduction processor 51e so that all repeated images can be fitted on the page. Then, the data in the compression processor 51h is converted back to quaternary data to be temporarily in the memory 53 save. The image processing CPU then loads 55 those in memory 53 stored downsized data and repeats it eight times to produce developed image data which is determined to represent 2 × 4 sections. The data developed in this way is stored in memory 53 saved.

If shadows are to be added to the image data as it is in this process, the image is rendered as in 26 is shown, with shadows running at 45 ° to the bottom right. In order to obtain a properly shaded image, the shading target pixel I is replaced with the pixel G when the shading process is carried out in this mode. Thereupon, the shading density conversion data processed in this manner is stored in the density conversion processor 51d exposed, so that the density of the shadows is converted to the fixed hue level '1', for example. While this process is running on the entire page, the image as in 27 is shown, added shadow with a length of one point in the lower left. If the resolution in this case 400 is dpi and shadows with a length of 0.5 mm are desired, the above procedure should be repeated eight times in order to complete the image data with the desired shadow. In the last stage, the image change / edit / composition processor combines 51c the silhouette data generated in this way with that in the memory 53 stored data of the original image to complete the shading process. The image data generated in this way are from the image data output unit 52 the laser printer system 2 fed to complete the operation. In this way, even when the image is rotated, by changing the selection of the shadow target pixel, shadows can be added in the same places as those created when the image is not rotated, whereby an image can be obtained that is free of incongruity.

As a function of image processing and image editing, the copier has an operation mode in which an image can be rotated so that it can be fitted on the side of a sheet if the manner in which an original document is laid differs from that of the paper differs. If, for example, to a 9 The original shown, which is in a different direction with respect to the normal position, shadows are added, which run below 45 ° to the bottom right, the operation being carried out without any particular change being made on the original image, as in 26 is shown, creates shadows that run at 45 ° to the bottom right. However, the output image has shadows that extend 45 ° to the top right when viewed in the same position as the original document.

In order to deal with the above situation, the following image processing is carried out. That is, if the user is using the control panel 54 sets the shading mode and, as in 9 is shown on the original table 5 or on the original document feeder (RDF) 6 arranging the original in A4 size in the reduction position (hereinafter referred to as A4R original), the original size sensor detects the original size and position and determines it as the A4R original. If under this condition all cartridges 35 . 36 and 37 A4 size sheets in the normal position, the output image is of course cut off if no treatment is done. To avoid this situation, the image processing CPU compares 55 based on the detected result of the size of the original and the information on the sheet size that is automatically detected when the cassettes are attached, the size and arrangement of the sheet with that of the original document. If the CPU 55 determines that the arrangement of the original differs from that of the paper, the CPU instructs 55 the image processing equipment 72 to rotate the picture.

More specifically, an image placed on the original is made by the image data input unit 50 processed and as image data in memory 53 stored so that in the image processing unit 51 a different process can also be carried out. Initially, the image data is processed by the error spreading processor 50c in the image data input unit 50 quantized into quaternary data and the quantized data temporarily in memory 53 saved. The image processing CPU then rotates 55 the image data by 90 ° clockwise. The image data rotated in this way is stored in the memory again 53 saved. The data is then processed by the added value processor 51a managed without being converted into 256-valued data by the added value process. Subsequently, this image data is subjected to the same shading process as that carried out in the copy retry operation described above, thereby doing as in FIG 27 full picture shown with shadow is obtained. On the other hand, the shading target pixel C can and should be selected if the image is to be rotated 90 ° counterclockwise. Thus, in this configuration, even if the arrangement of the original does not match the arrangement of the paper in the shading mode, not only the image data can be rotated, but another shading target pixel can be selected in accordance with the rotation of the image data. Thus shadows can be created in the same position as in the unrotated image. As a result, shading can be reproduced in a desired direction without considering the direction of arrangement of the original, whereby improved operational functions can be achieved.

When the shading and embossing mode is selected, the image pickup unit subsequently 7 an original picture of one on the original table 5 or on the document feeder 6 arranged document added. The captured image data are processed by the image data input unit 50 In the storage room 53 stored so that further various processes in the image processing unit 51 can be executed. Initially, the image data is stored in the error spreading processor 50c in the image data input unit 50 quantized to quaternary data. The data quantized in this way is stored in memory 53 stored and by the value creation processor 51a managed without being converted into 256-value data by the added value process. Thereupon, using the as in 8th 3 × 3 matrix shown in the image change / edit / composition processor 51c perform image processing of the image data. The like in 9 The data of the original image shown are supplied to the 3 × 3 matrix filter in the order (0.0), (1.0) ... (12.12), (13.12). A line buffer is arranged in front of the filter. In this arrangement, the filter is not able to process the data until the first three lines have been entered in the line buffer. The filter is set to have code for forming a maximum value of the density under an observed picture element E and the peripheral picture elements A, B, C, D, G, H and I.

As now in 10B is shown, the system, in order to form a maximum value of the density among an observed picture element E and the peripheral picture elements A, B, C, D, G, H and I as expansion target picture elements, determines that the observed picture element E and the expansion target Picture elements A, B and H have a density of level '3', while the other picture elements have a density of level '0'. Accordingly, it is determined that the maximum value is '3', so that the density of all expansion target picture elements is set to the level '3'. Repeated operations of the above process across the entire page of the image produce an image expanded by one picture element, as shown in FIG 28 is shown. As a result, the image thus generated is subjected to the shading treatment. Thereupon an expanded image with shadows with a converted density of level '2' is produced, as shown in 29 is shown. In the final phase, the image change / edit / composition processor removes 51c that in memory 53 stored original image from the expanded image with shadows so that a shaded and embossed image is created as shown in 30 is shown. The image data generated in this way are from the image data output unit 52 the laser printer system 2 fed, which in turn outputs a relief-provided image with one-point shadow.

• (1) Erzeuge aus einem ursprünglichen Bild durch Löschen irgendeines beobachteten Bildelements E mit einer Dichte vom Pegel '1' in den Daten des ursprünglichen Bildes ein mit Relief versehenes Bild.
• (2) Vergleiche die Dichte eines beobachteten Bildelements E mit allen peripheren Bildelementen A, B, C, D, G, H und I, um das Maximum zu bestimmen, und erzeuge aus dem beobachteten Bildelement E einen expandierten Einpunkt-Bildabschnitt.
• (3) Wiederhole den obigen Schritt (2) entlang der Randbildelemente, um ein expandiertes Bild zu vervollständigen.
• (4) Erzeuge einen Schatten für das expandierte Bild.
• (5) Vergleiche die Dichte jedes beobachteten Bildelements E mit der eines entsprechenden Zielbildelements I, um die Maximaldichte der verglichenen Bildelemente zu bestimmen.
• (6) Setze auf der Grundlage der Maximaldichte die Schattendichte um.
• (7) Wiederhole die obigen Prozeduren (5) und (6) in Übereinstimmung mit einer angegebenen Länge des Schattens mehrmals, um die Erzeugung eines Schattenbilds abzuschließen.
• (8) Schneide das ursprüngliche Bild aus dem expandierten Bild mit Schatten aus.

The above shading and relief process can be summarized by the following algorithm:

• (1) Create a relief image from an original image by deleting any observed picture element E with a density of level '1' in the data of the original image.
• (2) Compare the density of an observed picture element E with all peripheral picture elements A, B, C, D, G, H and I to determine the maximum and generate an expanded single-point image section from the observed picture element E.
• (3) Repeat step (2) above along the border pixels to complete an expanded image.
• (4) Create a shadow for the expanded image.
• (5) Compare the density of each observed picture element E with that of a corresponding target picture element I to determine the maximum density of the compared picture elements.
• (6) Based on the maximum density, implement the shadow density.
• (7) Repeat the above procedures (5) and (6) several times in accordance with a specified length of the shadow to complete the creation of a silhouette.
• (8) Cut out the original image from the expanded image with shadows.

In order not to highlight any glitches, here assumed that any image data with a density of less than the level '1' picture noise are while only the data with a density of level '2' or more is used to perform the relief formation operation.

If relief treatment is done only after steps (1), (2) and (3) above, he the following step follows as step (4):
(4) Cut out the original image from the expanded image to complete an embossed image.

Because an image loop for the extension treatment One-point outlines can and should loop twice be repeated to two-point outline to create.

Meanwhile, invisible small dust (or noise) could be picked up as image data when copying with an original document with stains and / or using the smeared original table 5 is carried out, whereby even the faults are expanded (and provided with relief). As in 31B an invisible stain (a disturbance) D expands (and is embossed) and one-pixel shadows are added to it, resulting in that in 31B shown picture leads. If shadows with a length of 0.5 mm are added to the stain, the resulting image will be as shown in 32 is shown, or spots (noises) with shadows with a length of 8 picture elements are added, whereby increased noises are generated. In order to avoid this situation, taking into account that disturbances from a small impurity and dust have a low density, the processing scheme is set up as follows. This means that a density quantized by means of a threshold value is built up for the observed image elements E, so that image elements with low density can be neglected when shading. The threshold density is set to level '1' here. If an observed picture element E has a density of level '1', the system stops the comparison between the observed picture element E and the target picture element I to determine the maximum of the two and the shading density conversion. When the copy operation is performed based on the scheme, the stain D , as in 33A and 33B is shown, not shaded and provided with relief. Although the above threshold density is set to level '1', this can be changed. In this way, no disturbances caused by contamination and stains, etc. are shaded and provided with relief or highlighted, so that a natural reproduction that is free from deterioration of the images can be carried out. This scheme is particularly effective when duplicating an original document that contains high-density characters and relatively larger characters.

Since it is difficult to distinguish blotches from an original image if the original document contains small characters and characters colored differently from black, the above measure does not work sufficiently. If a document in this case is like in 34A it is useful to distinguish stains by using dust and the like isolated. That is, in order to avoid a misjudgment between faults and characters, a 3 × 3 matrix filter is initially used in the as in 19 shown manner, so that the observed picture element E has a density of level '1', while the other surrounding picture elements have a density of level '0'. If an observed picture element E has a density of level '1', the system compares the density between the observed picture element E and the peripheral picture elements to determine their maximum. In this case, if all the surrounding picture elements have a density of the predetermined level (ie '0') and the density of the observed picture element E is less than the threshold density (ie '1' in this embodiment), the system determines that the picture element in question E is a perturbation, it does not perform the shading density conversion for the picture element. As a result, as in 34B is shown, the expansion and shading operation is performed as a result except for isolated spots of a single picture element, thereby outputting a shaded and embossed image as shown in FIG 34C is shown. In this way, disturbances due to dust etc. can be distinguished from valid picture elements. As a result, a natural reproduction that is free from deterioration of the images can be produced without highlighting any disturbances. This method is particularly effective when copying an original document containing small characters or an original of light colors.

The above two types of treatment can be applied to the relief mode. In the first treatment, an in 35A shown picture as in 35B shown processed and converted into a relief image, as shown in 35C is shown. In the second treatment, an in 36A shown picture as in 36B shown processed and converted into a relief image, as shown in 36C is shown. Since any disturbances caused by pollution and stains, like from one in 37 shown example, can not be provided with a relief, a natural reproduction that is free of deterioration of the images can be generated without any interference.

Since a shaded and embossed image is produced by cutting out an original image from an image expanded and shaded from the original image; In this way, if the density of the shadow after the density conversion is set as low as in the shading mode, for example to the level '1', the outline becomes indistinct. In order to avoid this, the shadow should be set to a higher level after the density conversion, for example to '2'. With this attitude he the relief appears sharp and thus enables a good reproduction result to be produced.

When the halftone mode is subsequently selected, the image data taken from an original is input through the image data input unit 50 In the storage room 53 stored, so that a different process in the image processing unit 51 can be executed. Initially, the image data is stored in the error spreading processor 50c in the image data input unit 50 quantized to quaternary data. The data quantized in this way is stored in memory 53 stored and by the value creation processor 51a managed without being converted into 256-valued data by the added value process. Thereupon, in the image change / edit / composition processor 51c using the in 8th 3 × 3 matrix shown, image processing of the image data is carried out. The like in 9 The data of the original image shown are supplied to the 3 × 3 matrix filter in the order (0.0), (1.0) ... (12.12), (13.12). A line buffer is arranged in front of the filter. In this arrangement, the filter cannot begin processing the data until the first three lines have been entered into the line buffer. The filter is set to have a code for forming a maximum value of the density among an observed picture element E and the peripheral picture elements A, B, C, D, G, H and I.

In order to form a maximum value of the density under an observed picture element E and the peripheral picture elements A, B, C, D, G, H and I as extension target picture elements, the system now uses 10B that the observed picture element E and the extension target picture elements A, B and H have a density of level '3', while the other picture elements have a density of level '0'. Accordingly, the maximum value is determined as '3', so that the density of all expansion target picture elements is set to the level '3'. Repeated operations of the above process across the entire page of the image produce an image expanded by one picture element, as shown in FIG 38 is shown. A grid pattern is developed, as described in 39A to produce a raster image as shown in 39B is shown. The above expanded image is cut out from the raster image, and then the resulting image is combined with the original image to be as in 40 to deliver the halftone shown. The image data generated in this way are from the image data output unit 52 the laser printer system 2 fed, which in turn outputs a single-dot halftone image.

• (1) Vergleiche die Dichte eines beobachteten Bildelements E mit allen peripheren Bildelementen A, B, C, D, G, H und I, um das Maximum zu bestimmen, und erzeuge aus dem beobachteten Bildelement E einen expandierten Einpunkt-Bildabschnitt.
• (2) Wiederhole den obigen Schritt (1) entlang der Grenz- oder Zwischenraumbildelemente, um ein expandiertes Bild zu vervollständigen.
• (3) Überlappe auf den Bereichen weißer Daten des expandierten Bildes ein Rastermuster, um ein Rasterbild zu erzeugen.
• (4) Kombiniere das ursprüngliche Bild mit dem Rasterbild, um ein Halbtonbild zu vervollständigen.

The above halftone process can be summarized by the following algorithm:

• (1) Compare the density of an observed picture element E with all peripheral picture elements A, B, C, D, G, H and I to determine the maximum, and generate an expanded single-point image section from the observed picture element E.
• (2) Repeat step (1) above along the boundary or space pixels to complete an expanded image.
• (3) Overlap a raster pattern on the white data areas of the expanded image to form a raster image.
• (4) Combine the original image with the raster image to complete a halftone image.

The above procedure only creates for the areas white Data of the expanded image is halftones, but does not puncture the Areas of black data (halftones or borders). Appear accordingly around the areas of black data gaps. Because in the conventional Halftone process of this type uses the entire image for dotting becomes the original Image deteriorated. In order not to deteriorate the original picture, alternatively, the edges are detected to halftone the areas designated as edges avoid. So this process took a lot of time. Because the process the invention in contrast no semitones for the original Image generated, can good reproductions be preserved. Because the process is so simple, processing efficiency can be reduced improved and thus the processing time can be reduced.

If the copying is carried out with an original document, as described in 41a is shown, has stains, and / or the original table 5 is used, which is smeared, subject to small stains D , as in 41B also shows the expansion conversion, consequently the spots D , as in 41C halftones, which leads to an unnatural output. In order to avoid this situation, taking into account that disturbances consisting of a small impurity and dust have a low density, the processing scheme is constructed as follows. That is, a density quantized by means of a threshold value is set for the observed image elements E in such a way that image elements with a low density can be neglected when shading. The threshold density is set to level '1' here. If an observed picture element E has a density of level '1' or less, the system stops the comparison between the observed picture element E and the target picture element I to determine the maximum of the two and the expansion process. Accordingly, the expanded image generated is as in 42A is shown. The image thus expanded is overlapped with a raster pattern to produce a raster image which in turn is combined with the original image to complete a halftone image as shown in FIG 42B is shown. In this way, malfunctions resulting from contamination and stains, etc. exist which would not be given halftones by the spaces, but would be amplified if the above noise reduction scheme was not used, will be provided with halftones. As a result, good reproductions can be made which are free from deterioration of images.

As previously described, had to the CPU in the conventional Image processing, if shading and expansion processes should take place, search all picture elements with densities and the widths of the picture elements extract to the size of the shadow and the line widths for to calculate the expansion. Accordingly, it takes longer processing time while the image to be treated becomes complicated. Accordingly, the present invention achieve high speed processing, since the shading and expansion operation is performed only by one simple folding operation for the pictures without consideration of the type of images can be made. Thus, the image processing of any images can be done even if they are complicated, done in a short period of time. Disruptions, caused by stains on the original or by contamination and dust from the original table or by any other factors be generated and in the conventional Processing would be highlighted be eliminated without any complicated processing is required. Consequently, the quality of the images in the copying operation this type of who improved.

It is noted that the present Invention should not be limited to the specific embodiments above but to the above embodiment within the scope of the invention, of course many changes and modifications added can be. For example, instead of reducing the density of the target pixel the density of the target pixel to a level higher than that of the observed one Image element can be adjusted when the shadows are emphasized should. Moreover can be the density of the image generated by image processing be set to any dark or light level. alternative can colors can even be added within a single page of the image. Besides, can any combination of image processing modes can be selected. More examples of Image processing modes include one mode for changing the Line thicknesses, an operating mode for shading white and an operating mode for relief formation and white shading.

Since the process of image processing, as is apparent from the above description, in accordance with the present Invention can be simplified, even a complicated one Image can be treated in a short period of time. So regardless of Type of images realized high speed processing become. Furthermore, the efficiency of image processing can be improved because all the image processing is done in a similar way can.

Because the density of the target pixel in accordance treated with the present invention according to the shade of a original Image changed can be faithful reproduction in the processed image an original Image are generated without its image quality deteriorating becomes. Moreover can be an original Image will be highlighted and if the original image halftone sections contains one size Diversity for the reproduced image can be generated without the quality of the original image to deteriorate.

In accordance with the present Invention can desired by the user Shadows are easily created, with a great variety for the image can be generated.

In conventional processing, a Image expanded from an original, the original Image to be removed from the expanded image and had to have outline lines generated before a shading operation was performed. On the other hand, in the present invention, shadows are caused by shading the expanded image and removing the original image from the expanded and shaded image. As a result, processing can be simplified, so that improved processing efficiency and a reduced processing time can be realized.

Because different from the state of the art the entire image of an original is not dotted if the original Halftone image can be provided, a well reproduced image can be obtained without any features of the original Image will deteriorate. Because the configuration of the present In addition, no invention Edge sections to look for can improve processing efficiency and a reduced processing time can be realized.

Claims (15)

Image processing device, with: operating mode setting means ( 7 ) that determine an image processing mode; Means of determination ( 72 ) that determine one or more target pixels in a two-dimensional image and in an environment centered on an observed pixel in accordance with the determined image processing mode; Means of comparison ( 72 ) comparing the gray level density of the observed picture element with the density of the one or more target picture elements and assessing whether the density of the observed picture element is equal to or less than a predetermined density level which lies between the maximum density level and a zero density level; and means of implementation ( 72 ), which is the density of the one or the plurality of target picture elements based on the comparison means ( 72 ) implement the results obtained, the implementation being blocked if the density of the observed picture element has been judged to be equal to or lower than the predetermined density level. An image processing apparatus according to claim 1, wherein the predetermined density level is the density level which has been arbitrarily determined to be provided for the one or more target picture elements, and the conversion means ( 72 ) are such that they convert the density of the one or more target picture elements into the predetermined density level. Image processing apparatus according to claim 1, wherein the converting means ( 72 ) are designed to distinguish the density of the observed pixel from that of the one or more target pixels. Image processing apparatus according to claim 1, further comprising: matrix construction means ( 51 ), which determine an arbitrary observed picture element and build up a matrix of picture elements which contains the observed picture element in its center and candidate picture elements for target picture elements around the observed picture element; Means ( 51 ) that select one or more target picture elements from the candidate picture elements around the observed picture element in accordance with a set mode of operation; Means ( 51 ) which operate each image processing means repeatedly over the entire image information to generate image information; and means ( 51 ) that generate an image by performing logic operations between the information generated by the image processing and information in the original image. An image processing apparatus according to claim 1, wherein the mode setting means ( 70 ) are designed to set any one of several image processing modes including a shading, a relief and a halftone mode, or one of these three combined image processing modes. The image processing apparatus according to claim 5, further with means that select a direction of shadows arbitrarily, thereby characterized by the selection of a target picture element in the manner it happens that from the candidate picture elements around the observed Image element target image element to be selected in the direction of shading with respect to the observed picture element located. Image processing apparatus according to claim 6, the shading operation includes the following steps: Run one Logic operation of comparing an observed picture element and a shading target pixel by a maximum value to obtain the density of both, the logic operation for each observed picture element above the entire original Image is repeated; Implementing the density of shadows to Generate shading image data; and Combine the original Data with the shading image data to complete a shaded image. Image processing apparatus according to claim 7, the one in execution the shading operation does not implement the density of the shadows accomplished becomes. Image processing apparatus according to claim 7, the one in execution the shading operation to the density of a target pixel a density is set lower than that of a corresponding one observed picture element is when the density of shadow is implemented becomes. An image processing apparatus according to claim 5, further comprising a system for the shading and relief mode, comprising: expansion means ( 51 ) which expand peripheral image elements around an observed image element on the basis of image information relating to an original image with a predetermined quantity of image elements; Shading agents ( 51 ) that add shadows to the image information about the expanded image that extend in a predetermined direction; and image processing equipment ( 51 ) which remove the image information about the original image from the image information about the shaded image. The image processing apparatus of claim 10, wherein the shading and relief operation comprises the steps of: performing a logic operation of comparing the density of an observed picture element and all of the expanded picture elements around the observed picture element to form a maximum value of those picture elements so as to form an expanded one-point Generate an image, the logic operation being repeated for each observed pixel along outlines across the entire original image to produce a fully expanded image; Shading the expanded image; Forming a maximum value of the density of an observed picture element and a shaded target picture element; repeating the density of shadows based on the result of the maximum formation operation between the observed picture element and the shading target picture element in FIG Matching a specified length of shadow until a desired, shaded and expanded image has been created; and removing the original image from the shaded and expanded image to complete a shaded and embossed image. An image processing apparatus according to claim 10, in the one in execution the shading and relief formation operation does not implement density the shadow executed becomes. An image processing apparatus according to claim 5, further comprising a system for the halftone mode, comprising: expansion means ( 51 ) expanding the peripheral picture elements around an observed picture element on the basis of picture information about an original picture with a predetermined quantity of picture elements in order to produce an expanded picture; Pattern generation means ( 51 ) that generate specific pattern information; Removal means ( 51 ) which remove the expanded image information from the image pattern information; and image processing equipment ( 51 ) which adapt the original image information to the image pattern information, a section corresponding to the removed information about the expanded image. An image processing apparatus according to claim 13, in the halftone operation involves the following steps: Run one Logic operation of comparing an observed picture element with all expanded target picture elements around the observed picture element, to form a maximum value of the density of those picture elements to so to produce an expanded single point image using the logic operation for each observed picture element along Gap picture elements above the entire original Repeating the image to produce a fully expanded image; overlap a grid pattern on areas of white data of the expanded Image to create a raster image; and Remove the expanded Image from the raster image and combining the original Raster image to complete a halftone image. An image processing apparatus according to claim 13, in the one in execution the halftone operation is neither a determination operation for the formation a maximum density of an observed picture element and expanding Target picture elements still perform an expansion operation.